This has been installed on my rifle, but has been sitting in my safe. There has never been any accessories installed on the rails themselves other than the rail covers. I'm including an extra new KAC barrel nut. The barrel nut that was used on the install has very little cosmetic wear only.

I bought both new from Valkyrietactical and they did the original install. ($448+$38 for the additional barrel nut=$486 plus shipping/tax)